Correlation among Physico-Acoustic Properties of Boscia angustifolia and Albizia adianthifolia Wood

Underutilization of some wood species can be largely attributed to a dearth of scientific information. Therefore, identifying the acoustic characteristics of lesser used wood species such as Boscia angustifolia and Albizia adianthifolia wood is expected to encourage their use in acoustic applications. Thus, studying their acoustic properties and the relationship among these properties will help reveal their use potential for acoustic purposes and also highlight possible predictor variable(s) for other acoustic parameters in wood acoustics. This study aimed at measuring the acoustic properties of B. angustifolia and A. adianthifolia wood and investigating the correlation among these properties. Three trees of each species were felled, and a total of 270 wood samples of 20 by 20 by 300 mm3 were collected. The samples were conditioned before acoustic measurement. The longitudinal free vibration method was adopted to measure the acoustic properties. Some of the mean acoustic results obtained for B. angustifolia and A. adianthifolia wood were 835.89 Hz, 3,657.51 m/s, 0.008, 13.59 GPa, 935.39 m4 kg−1 s−1, and 807.78 Hz, 3,542.66 m/s, 0.009, 12.65 GPa, 731.75 m4 kg−1 s−1, respectively, for fundamental sound frequency (FF), velocity of sound (V), damping factor (tan δ), specific dynamic modulus of elasticity (Es), and acoustic conversion efficiency (ACE). The correlation of FF with tan δ was negatively significant (−0.59), while it was positively significant with Es and ACE (0.99 and 0.74). This study found the two wood species suitable for making frame boards only and highlights sound frequency and velocity of sound as the major predicting acoustic variables for measuring good acoustic wood.

The Sound of Red Dust: Jean Toomer, Marion Brown, and the Sonic Transactions of “Karintha”

On his 1973 album Geechee Recollections, free jazzer Marion Brown tackles one of the most musical African American narratives, “Karintha” from Jean Toomer’s Cane. The velocity of sound Toomer’s text seeks to transcribe in literary form Brown trans-scribes back into music propelled by what I term Afro-kinesis. Afro-kinesis is a form of motion — a Benjaminian eddy rather than a Derridean trace — that improvises modalities of transaction with and in new-old sonic topographies, and in the process limns an aural modernity that constantly reinvents itself. This kinetic ecology of sound goes beyond acoustic transposition and instead aspires to effect a signifying exchange between the mercurial improvisation of free jazz’s “new thing” and the scripted stasis of literary text, a transaction of meaning across cultural time and physical space.

Physiscs Learning

To train this competence learning develop experimental topic that is contextual like experiment of analyzing material, determine standard tuning on the guitar, and calculate velocity of sound wave with doppler effect through the use of smartphones, the experiments that were presented is designed to facilitate scientific literacy competence and reading infusion is used to insert knowledge so that the students have enough knowledge, this is as able to develop attitudes and positive perspectives and productive thought process during knowledge formation, refinement of knowledge and application of knowledge.

The calculation of Binding Energy and Incompressibility, Pressure, and Velocity of Sound of Infinite Nuclear matter Using New One Boson Interaction.

The use of effective nucleon – nucleon (N N) interactions for the determination of nuclear matter properties such as, binding energy per nucleon, incompressibility,K of infinite nuclear matter, pressure 0 and velocity of sound of nuclear matter has been a subject of great interest to nuclear physicists for many decades. The effective interaction usually involved in these calculations has been the Michigan three Yukawa (M3Y) effective interactions whose origin is from G- matrix approach. In this research work however, we have used a newly developed interaction known as new one boson (NOB) effective interaction to carry out similar calculations. This new interaction is based on the Lowest Order Constrained Variational (LOCV) technique. The interaction reproduces the saturation energy of spin and isospin infinite nuclear matter of approximately -16MeV at the normal nuclear matter saturation density consistent with the best available density-dependent interaction derived from the G-matrix approach. The results of the incompressibility obtained using the NOB interaction ranges from 304 to 309 MeV. These values are in good agreement with the values of incompressibility obtained for similar calculations using the M3Y – Reid effective interaction, in which values for K range from 304 to 310 MeV. The results of 0 pressure and velocity of sound of infinite nuclear matter obtained in the present calculations are also in excellent agreement with results of other workers. The results of our present calculations indicate that, the NOB interaction has passed the basic test for an effective interaction. The NOB may therefore be applied to other nuclear matter and optical model calculations to ascertain its reliability.

Временные зависимости диэлектрических и акустических свойств в монокристаллах PbFe-=SUB=-0.5-=/SUB=-Nb-=SUB=-0.5-=/SUB=-O-=SUB=-3-=/SUB=- и PbFe-=SUB=-0.5-=/SUB=-Nb-=SUB=-0.5-=/SUB=-O-=SUB=-3-=/SUB=---7PbTiO-=SUB=-3-=/SUB=-

The time changes of permittivity, damping and velocity of sound are studied for PbFe_0.5Nb_0.5O_3 and PbFe_0.5Nb_0.5O_3–7PbTiO_3 single crystals in the electric fields of 0 < E < 6 kV/cm. The room-temperature local symmetry of these compounds is shown to be rather more monoclinic than rhombohedral, which is typical of other similar systems. No abrupt sound attenuation anomalies are observed upon the phase transition into the ferroelectric phase in the electric field. The effects seem to be far from the crystal symmetry changes and are attributed to the gradual transition of near-range monoclinic domains into long-range monoclinic domains, as well as to the emergence of the ferroelectric phase. The polarized phase induced in the electric field is only partially stable.

Упругие свойства монокристаллов La-=SUB=-0.7-y-=/SUB=-Pr-=SUB=-y-=/SUB=-Ca-=SUB=-0.3-=/SUB=-MnO-=SUB=-3-=/SUB=- (0≤ y≤0.3)

Results of the investigation of the temperature dependences of the velocity of longitudinal sound and internal friction in the ferromagnetic La 0.7-y Pr y Ca 0.3 MnO3 single crystals (0≤ y≤0.3) with first-order magnetic phase transition are presented. In the paramagnetic state, the temperature dependences of the velocity of sound and the internal friction demonstrate extended temperature hysteresis, which indicates the ingomogeneity of the paramagnetic state. It seems likely that the main reason of this ingomogeneity is structural phase separation.

Slow deformation fronts: model and features of distribution

Our study aimed at investigating the origin and development of ‘slow’ movements in a solid body/medium under loading and studying the role of such movements in the occurrence of critical states, i.e. sources of destruction in a stable solid medium. Computerized modeling was conducted to simulate the evolution of the stress-strain state and the formation of slow deformation waves in a loaded medium. We have developed and justified a mathematical model of the loaded elastoplastic medium, which demonstrates the joint generation and propagation of ordinary stress waves (propagating with the velocity of sound) and slow deformation waves of the inelastic nature. The propagation rates of the latter are 5–7 orders of magnitude lower than the velocity of sound. The features of slow deformation wave propagation in the solid media are investigated. In the model, slow deformation waves interact under certain conditions as solitons and penetrate each other. Considering the properties, they are similar to both solitons satisfying the solutions of the non-linear Korteweg – de Vries equation and kinks satisfying the solutions of the sin-Gordon equation. Slow deformation fronts are actively involved into the formation of sources of destruction and provide an effective mechanism for the transfer and redistribution of energy in the loaded medium.